New battery technologies are beginning to breakthrough into aerospace and automobiles applications. The safety of these batteries can be complex and their failures can lead to overheating. To address these safety concerns, new improvements in battery chemistries with less reactive cathode materials, new thermally stable electrolyte solvents and improved separator coating materials can be implemented. Additional solutions like enclosures can be implemented to circumvent thermal runaway from causing fires to other system from the battery overheating. An enclosure adds weight, however, and does not solve the overheating problem.